Endangered Status The Key Deer, a subspecies of the White-tailed Deer, is on the U.S. Endangered Species List. It is classified as endangered in Florida. The Key Deer declined in number as more and more of its habitat in the Florida Keys underwent development throughout the 20th century. Development continues to be a threat to the subspecies today. These tiny animals also fall victim to dogs and cars, and lose a significant number of fawns when they fall into drainage ditches. In 1961 the National Key Deer Refuge was established to protect the deer. The population has risen from a possible low of 25 animals in 1955 to about 250 to 300 today.